1. Field of the Invention
The invention is a device for the transmission of torque wherein the input element and the output element are in linear alignment. The device provides for variable, as opposed to stepwise, adjustment of the relative rates of rotation of the input and output elements. The preferred use for the device is as a variable speed transmission. The primary components of the device are a gyratory element or collar which oscillates but does not rotate and a rotating element which contacts the gyrating collar on a portion of, but not all of, its external or internal surface.
2. Prior Art
When a source of power is used to perform a task, it is often necessary to connect the power source to an element which is being driven through a device which changes the amount of torque and/or the speed of rotation so as to adapt the characteristics of the power source to the demands of the driven element. The device is known generically as a transmission. Historically, transmissions have employed either gears, pulleys or pumping devices. When gears are used, only specific ratios of input to output are available. To connect the power source to the transmission, a separate clutch is often required. Pulleys can be connected by belts and can provide fixed or variable ratios. Pulleys are limited in the amount of power which can be put through and have a speed ratio of no more than 6:1. Pumped transmissions are inefficient, complicated and often difficult to maintain. There exists a need for a reliable mechanical transmission which has a variable ratio, a very wide gearing range, is compact, easy to maintain and does not require a separate clutch.
Grant, U.S. Pat. No. 3,304,808, discloses a "gerotor" type reduction and reversing gearbox which operates at a fixed ratio and which has input and output shafts linearly arranged. Sfredda, U.S. Pat. No. 3,530,742 describes a variable ratio, planetary type transmission which employs a roller engaging a conical element connected to an output shaft. The power throughput is limited by the size of the roller and the direction of rotation of input and output shafts is reversed.